Why seven years of Tribulation?
Most of the Old Testament translations specify, in Daniel 9:27, the period called "week", which specifies already known 70 weeks of Daniel.
But, the word "week", as described in Daniel 9:27, does not mean "seven days". It means "seven years", according to the original Hebbrew text.
The original word, in Hebrew, is "SHABUA". It corresponds to a seven years period, not seven days.
Some of the English translations already bring this word correctly translated, preserving the real sense as in Hebrew.
Daniel 9:24-27 tells us why the Tribulation will last seven years:
Let's first observe, in Daniel 9:24, the parts in bold. This verse is the summary of the prophecies fulfilment for human kind destiny in God's hands.
The "seventy weeks" period corresponds to 70 × 7 years = 490 years (1 week = seven years). This period is designed for:
We observed that God established 490 years for this prophecy to get fulfilled. Based on this, Daniel 9:25 explains why Tribulation will last seven years:
"Know and understand this: From the issuing of the decree to restore and rebuild Jerusalem until the Anointed One, the ruler, comes, there will be seven 'sevens,' and sixty-two 'sevens.' It will be rebuilt with streets and a trench, but in times of trouble."
In above verse, God says in His prophecy that: between Jerusalem rebuild (started by Ezra, under authorization of king Artaxerxes) and the anointed (Jesus, in his first coming) there will be 7 weeks (7 × 7 years = 49 years) plus 62 weeks (62 × 7 years = 434 years), totalizing 49 + 434 = 483 years.
Important note: They are not continuous 483 years, because we know that, between Ezra book and Jesus' first coming, more than 483 years went by. This is a period specified by the prophecy, that gets gradually fulfilled in different epochs until they reach the 490 years.
When did these 483 years get fulfilled? The answer is in Daniel 9:26, when he says that the Anointed One will be cut off. This verse corresponds to Jesus crucification: his death, ressurection and going up in the sky. At this moment, the messiah, Jesus Christ, was cut off from earth.
So, until Jesus' first coming, 483 years passed, from the total of the 490 years of this prophecy. There are still seven years which did not get fulfilled yet.
These seven years left are in Daniel 9:27, that shows the antichrist signing up an agreement of peace (false peace) to Israel. This is still about to happen.